HI Lisa Qian
Welcome to Microsoft Q&A Forum, thank you for posting your query here!
I understand that you are encountering an issue, If you're using AI studio, the storage account needs to set CORS to allow AI studio to access the storage account, otherwise, you see the flow missing issue. You can add following CORS settings to the storage account to fix this issue. If you are resources are protected with virtual network, please make sure you have created private endpoints with storage and whitelisted IP and AI search/studio/OpenAI resources in storage firewall. storage-network-security
kindly refer below thread link: https://learn.microsoft.com/en-us/answers/questions/2047353/azure-ai-studio-prompt-flow-flow-is-missing-error
Thank You.